{blackbabes} RiRi's solo night

Rihanna celebrated a pal's birthday with a party of 30 at Marquee Friday night, without Chris Brown. The singer arrived at the popular Vegas club at about 2:30 a.m., spies said, then held court at a back table, heavily guarded by a security detail. Soon after, rappers A$AP Rocky and Snoop Lion dropped in and joined Rihanna's group as a birthday cake was brought out. They stayed out till 4 a.m. Then,"Some of them were overheard saying, 'The strip club is next!' " a source told us. No word on if they made it there.